scholarly journals Microbial Diversity in Cultivated and Feral Vanilla Vanilla Planifolia Orchids Affected by Stem and Rot Disease

2021 ◽  
Author(s):  
Ireri A. Carbajal-Valenzuela ◽  
Ariel H. Muñoz-Sanchez ◽  
Juan Hernández-Hernández ◽  
Francisco Barona-Gómez ◽  
Camille Truong ◽  
...  
Keyword(s):  
Microbial Diversity ◽  
Root Rot ◽  
Taxonomic Composition ◽  
Vanilla Planifolia ◽  
The Core ◽  
Worldwide Production ◽  
Fungal Microbiome ◽  
Rot Disease

Abstract The worldwide production of vanilla, a native orchid from Mexico, is greatly affected by stem and root rot disease, typically associated with Fusarium oxysporum fungi. We hypothesized that the presence of Fusarium species in vanilla is not sufficient for the plant to express symptoms of the disease. We described the taxonomic composition of endophytic microbiomes in symptomatic, asymptomatic vanilla plants using 16S and ITS rDNA metabarcoding, and ITS Sanger sequences generated from fungal isolates. We compared the bacterial and fungal diversity in vanilla plants from a long-term plantation, and from feral plants found near abandoned plantations that did not present SRD symptoms. No significant differences were found in the species richness of the bacterial and fungal microbiome among feral, or asymptomatic and symptomatic cultivated vanilla. However, significant differences were detected in both fungal and bacterial diversity from different organs in the same plant, with roots being more diverse than stems. We found that Proteobacteria and Actinobacteria, as well as the fungal families Nectriaceae and Xylariaceae, constitute the core of the vanilla microbiome that inhabits the root and stem of both cultivated and feral plants. Our work provides information on the microbial diversity found in root and stem rot in vanilla and lays the groundwork for a better understanding of the role of the microbiome in fungal diseases in vanilla cultivation.

scholarly journals Disease Incidence in Sugar Beet Fields Is Correlated with Microbial Diversity and Distinct Biological Markers

2019 ◽  
Vol 3 (1) ◽  
pp. 22-30 ◽  
Author(s):  
Peter Kusstatscher ◽  
Tomislav Cernava ◽  
Karsten Harms ◽  
Johann Maier ◽  
Herbert Eigner ◽  
...  
Keyword(s):  
Health Status ◽  
Microbial Diversity ◽  
Root Rot ◽  
Alternative Energy ◽  
Disease Incidence ◽  
Rrna Gene ◽  
Trophic Specialization ◽  
Internal Transcribed Spacer Region ◽  
Sugar Beets ◽  
Fungal Microbiome

Sugar beets (Beta vulgaris), which are one of the major sources for sugar, alternative energy, and fuel, are affected by several fungal pathogens at harvest time. In order to identify correlations between the microbiome of field-grown sugar beets and their health status before harvest, we studied 2,200 antifungal antagonists together with 73 amplicon datasets obtained with 16S rRNA gene fragments as well as the fungal internal transcribed spacer region in samples from 13 different field sites in Austria and Germany. Overall, a substantial loss of microbial diversity (bacteriome H’: 8 versus 6.5; mycobiome H’: 4.5 versus 3.5) as well as a substantially different taxonomic composition was observed in root rot-affected sugar beets when compared with healthy beets. The Gram-positive Lactobacillales as well as distinct fungal taxa such as Candida, Penicillium, and Fusarium were identified as indicators of root rot on the microbiome level. In contrast, higher microbial diversity as well as distinct fungal genera assigned to Vishniacozyma and Plectosphaerella were associated with the microbiome of healthy plants. The taxonomic shifts in the fungal microbiome were accompanied by trophic specialization; pathotrophic and symbiotrophic fungi were replaced by saprotrophic fungi in diseased sugar beets. Moreover, samples with high proportions of antagonistic bacteria were not vulnerable to shifts in the fungal microbiome. The overall findings show implications between microbial antagonists and plant health as well as key taxa that are indicative for the health status in beets. They provide the basis for the development of improved disease management systems and preventive counteractions.

scholarly journals Trade facilitation through logistics performance:The enabling role of National Government

2011 ◽  
Vol 5 (1) ◽  
Author(s):  
Jan H. Havenga
Keyword(s):  
Transport Network ◽  
Logistics System ◽  
Trade Facilitation ◽  
The Core ◽  
Rural Economies ◽  
Freight Logistics ◽  
Efficient Access ◽  
State Of Affairs

Despite two decades of visionary policies, problems within South Africa’s freight logistics system remain. Logistics costs are high, the current road and rail solutions will be unable to meet long-term demand for freight transport sustainably, and rural economies still do not have efficient access to the corridor transport network. This article postulates that one of the core reasons for the state of affairs is the inability of government to enable an optimally functioning freight logistics system. The main challenges faced by government are identified and an intervention is proposed to develop an overarching framework and implementation plan to address South Africa’s long-term freight logistics needs.

Role of toxins in etiology of root rot disease of wheat

1977 ◽  
Vol 55 (13) ◽  
pp. 1801-1806 ◽  
Author(s):  
Ross B. Pringle
Keyword(s):  
Root Rot ◽  
Toxic Substance ◽  
Toxic Metabolite ◽  
Root Rot Disease ◽  
Culture Filtrates ◽  
Helminthosporium Sativum ◽  
Rot Disease

Although no host-specific toxin, nor a great quantity of any toxic substance, has been found in culture filtrates of 26 different isolates of Helminthosporium sativum, the amount of the toxic metabolite, victoxinine, produced by these strains, may be correlated generally to their aggressiveness towards wheat.

scholarly journals Role of Bradyrhizobium japonicum and Trichoderma spp. in the control of root rot disease of soybean

2014 ◽  
Vol 30 (1) ◽  
pp. 35-40 ◽  
Author(s):  
Syed Ehteshamul-Haque ◽  
Abdul Ghaffar
Keyword(s):  
Grain Yield ◽  
Rhizoctonia Solani ◽  
Trichoderma Harzianum ◽  
Root Rot ◽  
Bradyrhizobium Japonicum ◽  
Seed Treatment ◽  
Trichoderma Spp ◽  
Root Rot Disease ◽  
Rot Disease

Seed treatment of soybean with <i>Bndyrhizobium japonicum, Trichoderma harzianum, T. viride, T. hamatum, T. koningii</i> and <i>T. pseudokoningii</i> significantly controlled the infection of 30-day-old seedlingsby <i>Maerophomina phaseolina, Rhizoctonia solani</i> and <i>Fusarium</i> spp. In 60-day-old plants <i>Trichoderma</i> spp.. and <i>B. japonicum</i> inhibited the grouth of <i>R. solani</i> and <i>Fusarium</i> spp., whereas the use of <i>B. japonicum</i> (TAL-102) with <i>T. harzianum. T. viride, T. koningii</i> and <i>T. pseudokoningii</i> controlled the infection by <i>M. phaseolina. Greater grain yield was recorded when B. <i>japonium</i> (TAI-102) was used with <i>T. hamatum</i>.

scholarly journals Silicon confers protective effect against ginseng root rot by regulating sugar efflux into apoplast

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ragavendran Abbai ◽  
Yu-Jin Kim ◽  
Padmanaban Mohanan ◽  
Mohamed El-Agamy Farh ◽  
Ramya Mathiyalagan ◽  
...  
Keyword(s):  
Protective Effect ◽  
Root Rot ◽  
Molecular Basis ◽  
Severity Index ◽  
Protective Role ◽  
Ginseng Root ◽  
Term Analysis ◽  
Root Quality

AbstractRoot rot caused by Ilyonectria mors-panacis is a devastating fungal disease leading to defect in root quality and causes reduced yield during the perennial life cycle of Panax ginseng Meyer. This indicates the imperative need to understand the molecular basis of disease development and also to enhance tolerance against the fungus. With this idea, the protective effect of silicon (supplied as silica nanoparticles) in P. ginseng root rot pathosystem and its molecular mechanism was investigated in the current study. We have tested different concentrations of silicon (Si) to disease-infected ginseng and found that long term analysis (30 dpi) displayed a striking 50% reduction in disease severity index upon the treatment of Si. Expectedly, Si had no direct degradative effect against the pathogen. Instead, in infected roots it resulted in reduced expression of PgSWEET leading to regulated sugar efflux into apoplast and enhanced tolerance against I. mors-panacis. In addition, under diseased condition, both protopanaxadiol (PPD) and protopanaxatriol (PPT) type ginsenoside profile in roots were higher in Si treated plants. This is the first report indicating the protective role of Si in ginseng-root rot pathosystem, thereby uncovering novel features of ginseng mineral physiology and at the same time, enabling its usage to overcome root rot.

scholarly journals MACROBENTOS OF VOZHE AND LACHA LAKES

2021 ◽  
pp. 77-93
Author(s):  
Ekaterina Pryanichnikova
Keyword(s):  
Taxonomic Composition ◽  
Water Bodies ◽  
Taxonomic Structure ◽  
Average Abundance ◽  
Average Biomass ◽  
Taxonomic Groups ◽  
River Communities ◽  
Faunal Similarity

The taxonomic composition of macrozoobenthos in lakes Vozhe and Lacha and in some sections in the Svid and Onega rivers is presented. The dominant complex in the lakes was formed by representatives of chironomids. Two species of oligochaetes and a gastropod were dominant in the rivers. The index of faunal similarity of macrobenthos between the lakes was rather high and amounted to 70%, while the similarity between the river and lake benthos was less than 30%. In the lakes, only two taxonomic groups were recorded, oligochaetes and chironomids that formed the basis of the benthos abundance: 87–93% of the average abundance and 92–95% of the average biomass in the lake. Oligochaetes and mollusks played a significant role in the river communities; in total, they formed 76% of the total abundance and 98% of the biomass. The trophic structure of macrobenthos in the lakes was almost similar, except the appearance of the group of phytodetritophages- filter-feeders in Lake Lacha. Detritophages-swallowers dominated in the river communities. In the previous studies of the lakes, the species richness of benthos both in Lake Vozhe and Lake Lacha was much higher. A decrease in the number of taxonomic groups and decrease in their abundance were observed in Lake Vozhe. At the same time, the role of chironomids in the formation of benthos in the lake was still significant. In general, changes in the taxonomic structure and abundance of benthos in lakes Vozhe and Lacha may be caused by a complex effect of environmental factors and long-term and intra-annual dynamics of dominant (cenose-forming) representatives of the main groups of macrobenthos. The simplification of the structure of the bottom communities, the inclusion of species with wide ecological spectra, the predominance of eurybionts among the dominants, may indicate pollution, eutrophication, and contamination of water bodies. According to the indicator species both lakes may be regarded as mesosaprobic water bodies.

All models are wrong, but some are useful: mathematical models at the time of Covid-19

2021 ◽  
Vol 07 (01) ◽  
pp. 115-130
Author(s):  
Roberta Buiani
Keyword(s):  
Public Health ◽  
Mathematical Models ◽  
Scientific Literacy ◽  
Historical Data ◽  
Epidemiological Models ◽  
Epistemic Values ◽  
The Core ◽  
Public Health Officials

Epidemiological models have been crucial tools throughout all stages of the 2020-21 Coronavirus pandemic: using promptly available or historical data, they have studied and tried to anticipate its progression, providing valuable guidelines for public health officials, policymakers, and other medical and non-medical audiences. While useful, models are not designed to be infallible, and for this reason, they have been frequently subject to criticism. There is a discrepancy between what models do and how they are presented and perceived. Several juxtaposing factors, including current beliefs about scientific reliability, the role of quantification, and the epistemic values grounding the field, are at the core of this discrepancy. While scientific literacy may play a role in addressing this discrepancy, analyzing and becoming better aware of these factors may suggest long-term strategies to address, acknowledge, and communicate the pandemic’s inherent complexity and stochastic qualities.

Percy Wragg Brian, 5 September 1910 - 17 August 1979

1981 ◽  
Vol 27 ◽  
pp. 102-130
Keyword(s):  
Research Station ◽  
Fungal Metabolites ◽  
Plant Physiologist ◽  
Metabolic Products ◽  
Fundamental Research ◽  
Antifungal Action ◽  
Rot Disease ◽  
Personal Research

Most of Percy Brian’s personal research was carried out while he was on the staff of Imperial Chemical Industries Ltd, over the 27 years 1936—63, first at the Jealott’s Hill Research Station and later at the Akers (formerly named the Butterwick) Research Laboratories at Welwyn. At the Akers Laboratories he pursued long-term problems with a devotion and precision worthy of the most fundamental research. His work, and that of the Department of Microbiology which he directed for some 17 years, was primarily concerned with fungal metabolites but it branched out in various directions that could hardly have been predicted at the outset. His work and thinking on the role of antibiotics in the microbial economy of the soil, once a very controversial subject, has influenced modern views more than any other. In 1946, no one could have predicted the outstanding practical success of the medical antibiotic griseofulvin, which is still unique in its mode of antifungal action and has become almost the perfect therapeutic agent for control of superficial mycoses in man and his domestic animals. Still more surprising was the later development of the gibberellins, at first known only as metabolic products of a fungus causing a foot-rot disease of young rice plants; later they were found to function naturally as hormones, widely distributed in the tissues of all kinds of plant. For this work on the gibberellins, Brian turned himself into a plant physiologist, as competent as he already was in mycology and plant pathology.

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